Mecanim - Transitioning to the same animation in reverse

In my game I have a character that starts in idle then transforms and stays motionless in that transformation. When the character transforms back to its original state, Idle, I want the transformation animation to play backwards as the character eases into its idle animation. Here's a visual flow:

    Idle <---------
     |             \
     V              \
 Transform --> Reverse Transform

My AnimatorController looks essentially just like this, but I feel this is a bit superfluous. I've tried transitioning back to Idle directly from Transform, but the character doesn't play the transform animation in reverse and just sort of falls back into the Idle animation, causing it to look odd.

In short, what's the simplest way to play the same transformation animation in reverse then go back to idle using Mecanim? Any help would be greatly appreciated!